During a hospital stay, ask for the itemized bill and check it line by line; ask first about self-paid items that insurance doesn't cover before agreeing; if the bill doesn't add up, first use the hospital's price complaint line, and if that fails, report to the medical insurance department

In plain words

During a hospital stay you can ask for the itemized bill, which lists the unit price, quantity and date of every drug and every test. For drugs and tests that medical insurance does not cover, except in emergency rescue, the hospital must first get the consent of you or your family. If you find duplicate charges, or charges for items that were not done, first call the hospital's price complaint line (价格投诉电话); if the hospital doesn't accept it, report it to the medical insurance department.